Former Sen. Rick Santorum (R-Pa.) revealed Wednesday night on Fox News that he is forming an exploratory committee in a quest to potentially seek the GOP presidential nomination.

Santorum says he has support, enthusiasm and positive feedback propelling him forward.

His hang-up? Campaign cash.

“[T]he test for me is whether we can raise the money that’s necessary,” Santorum told program host Greta Van Susteren. “And we’re going to determine over the next few weeks as to whether the resources are going to be there to do it.”

Santorum’s financial concerns also extend to his own pocketbook, as he’s said his personal finances are less than ideal.

So, unlike a Donald Trump or Mitt Romney, who stand to contribute tens, even hundreds of millions of dollars of their own wealth to their potential presidential campaigns, Santorum must rely on other people’s money if he runs.

Throughout his entire congressional career — including his years in the U.S. Senate and two terms as a congressman — Santorum raised a total of about $49.5 million.

The most prolific industries to contribute to throughout Santorum’s career varied, but dominantly came from the financial and business sectors.

The finance, insurance and real estate sector contributed more than $5.8 million to Santorum over his career, while the general business sector contributed about $3.8 million to him over the years, the Center’s research shows.

The most generous backers of his campaigns were retired individuals, who contributed more than $2.1 million.

The next most prolific givers among interests and industries tracked by the Center were lawyers and law firms, who also contributed $2.1 million.

The people and political action committees associated with the securities and investment industry, who gave nearly $1.6 million, round out Santorum’s top three industry donors.

Santorum served as a U.S. senator from 1995 until 2007.

And although he has been out of political office for more than four years, Santorum has stayed heavily involved in the world of money-in-politics.

Ahead of last November’s election, America’s Foundation doled out $43,000 to GOP House candidates and $42,000 to GOP Senate candidates. Many of these contributions have gone to Pennsylvania Republicans running for political office.

America’s Foundation also contributed $1,000 to the Republican Party of Iowa. Iowa has traditionally been an important state in the presidential nomination process because of its first-in-the-nation caucus, where Santorum hopes to connect with conservative voters who share his opposition to abortion rights and same-sex marriage.

Other Republicans who have announced presidential candidacies or exploratory committees include former Speaker of the House Newt Gringrich, former Minnesota Gov. Tim Pawlenty, former Massachusetts Gov. Mitt Romney, former Louisiana Gov. Buddy Roemer, former Godfather’s Pizza Chief Executive Officer Herman Cain and former GOP operative and gay rights activist Fred Karger.

Other high-profile Republicans — such as former U.S. ambassador to China John Huntsman, former Arkansas Gov. Mike Huckabee, former Alaska Gov. Sarah Palin, Mississippi Gov. Haley Barbour, Rep. Michele Bachmann (R-Minn), Rep. Ron Paul (R-Texas) and businessman Donald Trump — are also flirting with the possibility of seeking the GOP nomination in the race against President Barack Obama.

Despite his financial obstacles and wealth of competition, Santorum is certainly acting like a confident candidate, following his Fox News announcement up with an email blast to his supporters.

“It’s time for America to be America again — an America that rewards innovation and hard work, that stands by our allies instead of our enemies, that protects even the most vulnerable of our society, and an America that says every life is to be cherished,” Santorum said in the email. “That’s what I believe in and that’s why I’m taking this next step in a possible run for president.”

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